Cancer Care on the Cutting Edge
By DAGNY STUART
For decades cancer therapy was limited to various forms of surgery, chemotherapy and radiation therapy. Today, advances in cancer therapy are occurring at an accelerated pace, and Nashville physician/scientists are on the leading edge of these treatment advances.
More than 22,000 women are diagnosed with ovarian cancer every year, and in about 80 percent of those cases, the cancer has already metastasized to distant sites in the body. For patients with advanced ovarian cancer, the disease often recurs within a few years after initial treatment and is fatal.
Michael Stany, MD
At Saint Thomas Cancer Care, gynecologic oncologists Michael Stany, MD, and his partner Jason Cory Barnett, MD, are using a predictive test to help determine how each patient's tumor is likely to respond to a chosen treatment or combination of therapies.
They are enrolling patients in ANCERS-2, a National Cancer Institute-sanctioned clinical trial, testing the new CANscript™ sensitivity assay, which mimics the tumor microenvironment to help predict tumor response to selected therapies. Using tumor tissue and blood samples, the CANscript assay recreates the immediate surroundings of an individual's tumor to evaluate that patient's likely response to treatments chosen by the physician.
"Cancer doesn't obey the rules of cell growth and division, and the microenvironment of an individual patient's tumor is unique, with molecular interactions that determine whether cells are living or dying," said Stany.
Current ovarian cancer therapies include various types of chemotherapy, plus VEGF inhibitor drugs like bevacizumab (Avastin) that block blood vessel growth and new PARP inhibitor drugs. While these standard therapies and novel drugs offer more care options, physicians can't predict how an individual patient's cancer will respond. By recreating the tumor's ecosystem, the CANscript assay hopes to offer better insight into reaction to these options used either individually or in combination. In early tests using the assay, there has been a higher correlation to clinical outcomes, which has provided an opportunity for more personalized care.
Stany said this trial, open for enrollment to patients with recurrent ovarian cancer, is offering guidance to physicians about which chemotherapy or combination of therapies is likely to be effective to enhance individualized care and improve patient outcomes.
Cancer cells feature a cloaking mechanism that enables them to evade attack from the body's immune system, but scientists are using new technology to deliver a lethal blow to these rogue cells by enabling immune cells to lock onto specific proteins on those cancer cells. CAR T-cell therapy is among the most promising areas of cancer research, and Sarah Cannon is one of the leading research organizations offering this new treatment to patients.
In CAR T-cell therapy, physicians obtain the patient's blood and isolate T lymphocytes, which are shipped to special laboratories where a gene for a receptor called a chimeric antigen receptor (CAR) is inserted into the T-cell. Millions of the CAR T-cells are grown in the lab, then shipped back to the hospital and infused into the patient. The CAR T-cells bind to a specific antigen on the cancer cells, specifically CD19 or CD22 in lymphomas and leukemias, and destroys them.
The initial clinical trials for CAR T-cell therapy were initiated for adult patients with lymphomas and pediatric patients with Acute Lymphocytic Leukemia. "These were patients who had poor prognoses because other therapies had proved to be ineffective," said Carlos Bachier, MD, program director for Blood and Marrow Transplant for the Sarah Cannon Blood Cancer Network and leader in CAR T-cell therapy research at Sarah Cannon Center for Blood Cancer at TriStar Centennial Medical Center in Nashville.
"In CAR T-cell clinical trials for lymphomas, about 75 to 80 percent of those patients have gone into remission. Now with a follow-up of approximately two years, approximately half are still in remission and may be cured. This is a significant advance in a population where remissions are rare and survival is less than six months," noted Bachier.
Some CAR T-cell therapies have now been FDA approved for blood cancers, including pediatric Acute Lymphoblastic Leukemia (ALL), and non-Hodgkin's Lymphoma in adults.
Bachier said Sarah Cannon's research infrastructure and deep physician expertise have enabled them to offer many new clinical research trials to cancer patients. "We treated our first patient in a clinical trial in April 2016. Since then in Nashville, we have treated 47 patients, and in the entire network, we have treated more than 60 patients. In Nashville, we currently have 23 clinical trials with these immune effector and CAR T-cells in a variety of malignancies, including blood cancers like lymphomas and leukemias, and solid tumors including lung cancer, breast cancer and other solid tumors."
Patients with early or intermediate-stage prostate cancer who choose radiation therapy used to need up to 44 radiation treatments to eliminate their cancer. Now Vanderbilt-Ingram Cancer Center (VICC) provides high dose stereotactic body radiotherapy (SBRT), which enables men to be treated in far less time, as few as five treatments, with low toxicity.
With SBRT, physicians deliver a high dose focused beam of radiation to the tumor. Long-term follow-up studies have shown excellent rates of cancer control.
While prostate tumors typically respond well to radiation therapy, there is a risk of damage to adjacent tissues, including the bladder, sex organs and rectum. So VICC radiation oncologists are utilizing a hydrogel spacer to create a space between the prostate and nearby healthy tissues to increase the safety of the new technique.
"The hydrogel spacer acts like an epoxy," explained Eric Shinohara, MD, MSCI, associate professor and vice chair of Radiation Oncology. "You inject two syringes of materials that mix together and harden into a substance like a jelly, creating a space between the rectum and the prostate. This allows us to dramatically reduce the radiation dose to nearby tissues and minimize unwanted side effects."
During radiation therapy, the hydrogel spacer remains stable and is gradually absorbed by the body after the treatments have been completed. This ability to deliver high doses of radiation therapy in a short time span provides more convenience for patients as well as enhanced recovery time.